Vibrating screen



April 25, 1933. B. E. GREEN VIBRATING SCREEN 2 Sheets-Sheet 1 Filed March 3, 1950 INVEN m I HEM:

ATTO NEYS April 25, 1933. B 5 GREEN 1,905,393"

' VIBRATING SCREEN Filed March 5, 19 30 2 Sheets-Sheet 2 INVENTOR ATTORNEYS Patented Apr. 25, 1933 UNITED STATES PATENT OFFICE BURNETT n GREEN, OFIALQPENA, MICHIGAN, AssIeNoa T0 HURON INDUSTRIES, me,

or ALPENA, MICHIGAN, A comeonnnon or MICHIGAN VIBRATING SCREEN Application filed March 3, 1930. Serial No. 432,667.

The present invention pertains to a novel vibrating screen particularly adapted for use in the stone, sand and gravel industry to efliciently handle wet or dry material to facilitate accurate sizing of the separated materials. The device is further adapted for use in any of the industries requiring means for separating various sizes of materials, such'as the coal grading industries.

A primary object of the present invention is to devise a screening machine provided with a mechanism adapted to impart a vibratory motion to a screen supporting frame having resilient and adjustable supporting members, resulting in an efiicient siftingor screening action being imparted to material passing over said screen. The vibrating motion is derived from an eccentric shaft that is connected to the central portion of the screen frame which is supported by connecting members adjacent its ends connected the base by means of quarter elliptic leaf springs, the latter ermitting jerking or rocking movement 0 the screen frame, the jerking or rocking movement resulting from the oscillatory movement of theeccentric and being a result attained only by the particular type of spring disclosed by the present lIlVGIltlOlL The eccentric mechanism facilitating the screening movement is designed to efficiently operate under all conditions, maintenance cost being reduced to a minimum by efficiently enclosing the moving parts and hearings in a manner excluding dust or grit coming from the material being screened which would clog the bearings and cause considerable wear'and expense and prevent satisfactory operation of the device.

With the above and other ends in view the invention consists in the mattershereinafter set forth and more particularly pointed out in the appended claims, reference being had to the accompanying drawings, in which Figure 1 is a side elevation of the present screening machine;

Fig. 2 is a transverse cross sectional view taken on the line 2-2 of Fig. 1, and

Fig. 3 is a fragmentary detail of one of the screen frame supporting brackets.

Like characters are employed throughout to designate the correspondingparts. j

The screen comprises a pair of side plates 1 having secured thereto inwardly projecting angle irons 2 to which are secured brackets 3 adjacent the four corners thereof. The screen proper is indicated by the numeral 4 and is secured upon the angle irons 2 by means of the straps 5 that are bolted thereto. The brackets 3 support cross shafts 6 which extend transversely between the brackets mounted upon the opposite angle irons, the shafts 6 projecting outwardly to pivotally support bearing blocks 7. In one end of each block is screwed the end of Onebfthe screws 8, the opposite ends of the screws being screwthreaded in the U brackets or shackles 9 to which are connected the quarterelliptic springs 10. The springs 10 are suitably bolted or secured upon the'base member 11 to project outwardly and upwardly from both ends thereof. a

It is necessary that the screen should be supported in'an inclined position and this is accomplished by having the members 3, 7, 8 and 9 supported below the springs at one end of the structure while the corresponding members at the opposite end of the structure are supported above the springs. It will also be noted that opposite ends of the screws 8 are oppositelythreaded to permit adjustment of the space between thespring and the corresponding bracket 7 by simply rotating the receive the bearing races 14 that are provided to support the ends of shaft 15. To make these bearings dust proof there are provided caps 16 each having a projection 17 received in the bore of the bearing bracket, the caps being secured in any suitable manner and having packing glands 18 to engage the shaft 15.

The shaft 15 is formed with an eccentric portion 19 which is formed on the portion of the shaft supported between the bearings 14 and this eccentric portion is surrounded by the bearing races 20 mounted adjacent the ends thereof. The bearing races are received in a circular bore in the bearing brackets 21 which are-secured to the screen frame and the outer face of the bearing bracket is covered by a cap 22 having suitable packing glands and being formed to prevent dustor grit from entering the circular bore in the bracket. The inner faces of the bearing brackets 21 are covered and made dust proof by the outwardly projecting flanges 23 formed on the sleeve 23 which extends between the two brackets to completely enclose the shaft 19.

On the outer ends of the shafts 15 are mounted flywheels 24 having balancing weights25 secured thereto to counter-act the weight of the eccentric shaft and insure smooth running thereof. To one of the flywheels is attached a pulley 26 to receive a belt driven from any suitable power source in order to operate the present screen.

Smooth running of the shaft 15 and portion 19 is insured by providing counter-balanced flywheels and by providing bearings which are so enclosed that they are not affected by the dust or grit coming from the material passing through the screen. The

screen is supported by a special type of spring and by mounting the bearing brackets 21 to the screen frame intermediate its ends the eccentric shaft 19 imparts oscillatory movement to the screen and the springs convert the oscillatory movements into a highly eflicient vibratory or screening movement.

What I claim is:

1. A device of the character described comprising a base, a screen-supporting frame, front and rear multi-leaf quarter elliptic springs disposed lengthwise in spaced apart parallel relation to said frame and base and having one end secured to said base and the other pivotally shackled to said screen-supporting frame, variable-length connecting means between said springs and said screen adapted to support said screen in an adjustably inclined position, and a transverselydisposed eccentric drive shaft supported by said base and connected to said screen frame whereby rotation of said shaft causes vibration of said screen.

2. A device of the character described comprising a base, a screen supporting frame, front and rear multi-leaf quarter elliptic 7 springs disposed lengthwise in spaced-apart parallel relation to said frame and base and having one end secured to said base and the other pivotally shackled to said frame, adjustable-length connecting shackle members mounted on the outer ends of each of said springs and adapted to support the screensupporting frame on their opposite ends and maintain the frame in an inclined position, and a transversely disposed eccentric drive shaft supported by said base and connected to said screen frame whereby rotation of said shaft causes vibration of said screen.

3. A device of the character described comprising a base, a transversely-disposed drive prising a base, ascreen-carrying frame resiliently supported by front and rear multileaf quarter elliptic springs disposed lengthwise in'spaced-apart relation to said frame and base andmounted' on said base, adjustable-length connecting shackle members between said frame and saidsprings adapted to support said screen frame in an adjustably inclined position, and eccentric-shaft means for vibrating said screen frame.

5. A device of the character described comprising a base, a screen-carrying frame resiliently supported by front and rear multi-v leaf quarter elliptic springs disposed lengthwise in spaced-apart parallel relation to said frame and base and having one end secured upon said base, adjustable-length shackling members pivotally connected to said frame and to said springs and adapted to support said frame in an adjustably inclinedposition, and eccentric .shaft means mounted upon said base and connected to said frame to impart-vibration to the latter.

6. A device 'of the character described comprising a base, a screen-carrying frame resiliently supported by frontand rear multileaf quarter elliptic springs disposed lengthwise in spaced-apart parallel relation to said frame and base and having one end secured upon said base and the other end shackled to said frame, adjustable-length shackling members pivotally connected to said frame and to said springs and adapted to support said frame in an adjustably inclined position, a transversely-disposed drive shaft mounted on self-aligning anti-friction bearings carried in dust-proof housings, an eccentric formed on said shaft, and connecting members between said eccentric and said frame whereby rotation of said eccentric causes vibration of said screen.

7. In vibrating screening apparatus of the class and character described, a base member for supporting a horizontal transverselydisposed counterbalanced drive shaft journaled in self-aligning anti-friction bearings enclosed in dust-proof pillow-block casings mounted on said base member, said drive shaft having an eccentric portion journaled in similarly encasedself-aligning anti-friction bearings mounted in members attached to the underside of frame members -supporting a screen, said screen and its supporting frame being vibrated by said eccentric portion of said drive shaft when latter is rotated, front and rear multi-leaf quarter-elliptic springs disposed lengthwise in spaced-apart parallel relation to said screen frame and attached at one end to said base and at the other end to adjustable-length shackling links pivotally connected to said screen-supporting frame members above said drive shaft, said links serving as double-purpose means for varying screen inclination and spring tension at will to modify the reaction of springs at one side of said drive shaft in relation to reaction of the springs at the opposite side of said drive shaft.

In testimony whereof I a'ffix my signature.

BURNETT E. GREEN. 

